Stabilized fuel oils



United States Patent *ice de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application April 7, 95 2, Serial N0. 281,047

11 Claims. o1;- 44 -62) This-- invention relatesto-stabilized -fuel oils filldgw'lflOIE 15 particularly to fuel oils adapted to withstand without; deterioration the prolonged oxidizing; conditions. of storage. This application is a continuationin partof-ap plicants copending application Serial No. 214,855, filed March 9, 1951, and abandoned April 12, 1952.

Fuel oils, that is,hydrocarbon oils boiling above the gasoline range andusedas burner and fur'naceoiIsand diesel fuels and the like, are produced not only from straight run petroleum hydrocarbon distillates' but, alsd, by thermocracking and catalytic cracking; Until; cently, m'o's't" fuel oils have been straight run" butca'tal'y'tic cracking is fast becoming the most popular. method for supplying the increased demand for fuel oils.' V i Fuel oil blends containing substantial propfor tion'siof. catalytic cracked stocks, e.-g';, fromapproxirriatelyfiQ-fiii to 60%" by'wei'ghtofthe' blend", withstraight run fuel; oils are now being marketed; It would be preferablel'itd increase the proportion of catalytic cracked oil o1: sell catalytic cracked oil exclusivelyfor fuel urposes but. this not been practical because of a serious storage'? stability problem. 7

Fuel oils are frequently prone todeti'ioration on storage" and catalytic cracked fuel oil particular'is' fie quently very' unstable and deteriorates in storage; The deterioration resulting from themild butprolonged; 40 oxidizing conditions of storage results not only generally in discoloration but inthe formation of sludge or sediment which, if not removed, plugs filter screens, orifices, and: other parts of the-equipmentused in burning such fuel.- The high susceptibility to deterioration'ofmany catalytic. crackedfuel oils has made it-necessary to blend tbem otl with larger proportions of the-"less plentifulbutmore stable-straight run stocks to meet even= the miniw mum stability: requirements. Nevertheless, difliculty has' beenexperienced with such fuels and-refiners are fre-, quently forced to take back from the. distributorsoii with considerable oil; insoluble residue.

The. problem of stabilizing catalytic cracker? fueloilsis. relatively new. Because ofits importance thereis a great deal of activity in the field ofadditivesto stabil-ize fuel oils, but no really satisfactory solution to the problem has been devised. Another approach to the problem has been to develop refiningitechniques or treating processesi to remove the unstable components of catalytic cracked: fueloil to-improve-its storage stabilitys Some refiners -have been able to achieve quality improvements? bycertain treating: methods, suchas acid washirigi'ofixthe? oil; butthesermethods are toocostly for commercialiarr"' plication: and do not" seem to present a 'solutionatothe problem. Also, while catalytic cracked-fuel oils are the worst performers-lathematterof deterioratio'n: during;- storage; the problem-does existto greater or lesser degree with fuel oils generally.

An object of the present invention is to provide an improved stabilized fuel oil? A further object is to providea stabilized fuel oil containing atleast a substantial proportion'of catalytic cracked'oil. A'- still fiii-thr and 2,737,452 Patented Mar; 6-, 1956 2.. more specific object is to provide'a stabilized catalytic cracked fuel oil which may be stored without deterioratiou. Other objects will be apparent-from the description of the invention given hereinafter. v I

Tl ile aboveobjects aref accomplished a'qcording-tof the. present" invention"by incorporating in a fuel oil a small proportion, atleast 0.001% by weight of 'th e" fuel'oil, of

-soluble, basic amino nitrogen-containing additi n g 'of a' plurality ofpoly'meriz'ablef e'thyleln; cally u aturatedcompounds', at least one OfwhiQh'is dcontains from 8 to about l8 carbon atoms .e j c r n c ai ch th i ie y r is"- not part of the main polymer chain preferably pre? dominantly straight chain in nature, andorie of which as it exists in the polymer. contains a basic amino nitrogen in the side chain, saidpolymer' containing 0.1% to 3.5%, by weight thereof, of basicamino nitrogen. V

The optimumproportion of polynie ri irl the fuel oil g ined by: its inherent'vis'cos'ity, whichcarr'" b'e wit'li-in the range of 03116320 as determined at 6.1% "ohime conceiitration iabenzeneat 25'? C. Fioa r a practical" point of view, 0l0'0l a) 0.1% of th olymer" additive having an inherent viscosity between abou and 1.0,- normally will be found as give op ti'rriunr results:

Altho'u'ghf the medians-Hr by 'w hicli' the ful'o'il" compdsitioris' oftliis' invention ope ate} ifs"1'10t known; 6X" mental work both 'inlaboratory} and practical tests v has established" certain basic re uirements; for addition type polymers as regards compositions, st

leas one of the monomeric components employed iii making the poly'r'ner' sh'o'iild introducea'ii oil-solubiliizing f or 01 'p'hilic structure to insure that the poli'qner so bl iawhe eit'ent of at-leastfOYOlllQSlby weigh tin,

copolyrn'en and should; be within the range of 0 1% to 3- 5;% introduction of 'the basic-* amino nitrogem structure can be accomplished by. the use of at least one monomeric component containing the; aminogroup: or

by; use'of a monomer-'- containing a group'whic'h is" reac' tive, .when present in the polymer, toward ammonia; or: primary orsecondary nonaromatic amines-.- ,These" monomers can also contain oleophilic structures that will= assist in=contributing-. to therequisite-*oilsolubility. In addition, some of the polymers coming within the scope. ofthis invention can,"without-sacrificing-either fuel oil solubility, or sludge inhibiting.- and dispersing.- properties-, include j certain proportions of monomers that do notthemselves= yield oil-soluble polymers.

Copolymersuseful in the practice of the-*invention ean be-prepared by conventiona'lbulk;=solution,-'1ordispersion polymerization methods 7 involving known initiators, in cliidiirgioxygen yieldingk compounds, such asbenzoyl p r oxide, and-' azo' compounds, suchas alpha,'alphaaz6diiso buryroriitnle convenient solvents re high borh'n'g by: drbcarboiis', articularl those siir'iilar to'thef' f die'carej s in which the copolymers are to be usedisiich' askero'sehe'." The polymerization processes usually are carried out in an inert atmosphere, e. gf, nitrogen or carbon dioxide, at temperatures rangingfrom 30 C. to C., depending'ji n' the catalyst used, and generally at temperatures between. 50 C. and 70 C.- when;alph a,alphaf azodiisoso that nounpolymerized monomers remain and the pro- H p A tiire'i aii d physic'aIprbpertieSE I For eiiampla-it' is iess'e at; that at portions of each component in the final product are es sentially those of the original monomer mixture.

The following examples wherein all parts are by weight unless otherwise stated, illustrate typical polymers adapted for use in the present invention.

EXAMPLE I 47.5 parts of n-octyl methacrylate, 2.5 parts of betadiethylaminoethyl methacrylate, and 0.25 part of alphaalpha'-azodiisobutyronitrile were heated together in a polymerization reactor under an atmosphere of oxygen- EXAMPLE H Similar results were obtained when kerosene was used in.

place of mineral oil.

The technical lauryl methacrylate used in the preparation above is the methacrylic acid ester of technical lauryl alcohol which is obtained by reduction of the fatty acids of coconut oil and is a mixture of saturated straight chain alcohols ranging from about to 18 carbon atoms. A typical example will contain approximately 3%, C10, 61% C12, 23% C14, 11% C16 and 2% C18 alcohols.

EXAMPLE III 170 parts of technical lauryl methacrylate, 20 parts of methacrylanilide (N-phenylmethacrylamide), 10 parts of glycidyl methacrylate and 1.2 parts of alpha,alpha-azodi isobutyronitrile were heated together in a polymerization reactor for 8 hours at 65 C., as in Example I. The 85/ 10/5 lauryl methacrylate/methacrylanilide/glycidyl methacrylate copolymer thus obtained was removed from the polymerization reactor and thoroughly mixed with twenty-two parts of technical diamylamine (2 molar proportions based on the copolymer) by careful milling on a two-roll rubber mill. The resultant mixture was placed in a closed container and warmed for 24 hours at about 60 C. to complete the reaction of the amine with the epoxide structures in the polymer. This reaction involves scission of the oxirane rings in the glycidyl methacrylate units by the diamylamine to give units containing gamma-diamylamino-beta-hydroxypropyl radicals as more fully disclosed in application Serial No. 176,918, filed July 31, 1950, now abandoned, in the name of M. E. Cupery, assigned to the assignee of this application. The final product is thus a lauryl methacrylate/methacrylanilide/gamma-diamylamino beta hydroxypropyl methacrylate copolymer.

EXAMPLE IV 90 parts of technical lauryl methacrylate and 10 parts of glycidyl methacrylate were copolymerized as in Example II by heating at 60 C. for 24 hours in solution in 100 parts of highly refined petroleum white oil in the presence of 0.6 part of alpha,alpha'-azodiisobutyronitrile.

" methacrylate/beta-diethylaminoethyl To the oil solution of the copolymer thus obtained there was then added 9.4 parts of technical diamylamine (0.85 molar proportion based on the copolymer) and the mixture was heated to C. for about 1 hour to effect reaction of the diamylamine with the oxirane rings in the glycidyl methacrylate units in the copolymer in the manner explained in Example III, to obtain a white oil solution of a lauryl methacrylate/glycidyl methacrylate/gamma-diamylamino-beta-hydroxypropyl methacrylate copolymer.

EXAMPLE V A mixture of 19 parts of vinyl laurate, 1 part of allyl glycidyl ether and 0.12 part of alpha,alpha-azodiisobutyronitrile was heated for 6 hours at 65 C. as in Example III. To the resulting /5 vinyl laurate/allyl glycidyl ether copolymer was added 1.1 parts of technical diamylamine and the reaction mixture allowed to stand for several days at room temperature. There was thus obtained a fuel oil-soluble vinyl laurate/allyl glycidyl ether/allyl gamma diamylamino beta hydroxypropyl ether copolymer.

EXAMPLE VI A pressure-resistant reaction vessel was charged with 20 parts of beta-diethylaminoethyl methacrylate, 50 parts of 2-ethylhexyl acrylate and 0.5 part of alpha,alpha'- azodiisobutyronitrile. The vessel was closed, flushed with nitrogen and evacuated, pressured with isobutylene under 3000 atmospheres pressure, and heated with agitation for 4 hours at about 65 C. The reactor was then cooled, vented to the atmosphere and the resinous product removed. There was thus obtained a 69/ 16.4/ 14.6 2-ethylhexyl acrylate/beta-diethylaminoethyl methacrylate/isobutylene copolymer as a fuel oil-soluble, viscous, tacky resin.

Another copolymerization reaction was carried out as above, with 40 parts of lauryl methacrylate, 10 parts of beta-dimethylaminoethyl methacrylate, 50 parts of benzene, 0.5 part of alpha,alpha'-azodiisobutyronitrile and ethylene under 1000 atmospheres pressure. There was thus obtained a 64/18/18 lauryl methacrylate/beta-dimethyl/aminoethyl methacrylate/ethylene copolymer as a fuel oil-soluble, viscous, tacky resin.

EXAMPLE VII 80 parts of sec.-capryl methacrylate (B. P. 70-72 C./0.50.7 mm. of mercury), prepared by ester interchange of sec.-capryl alcohol with methyl methacrylate in the presence of tetraisopropyl titanate as catalyst (as was fully disclosed in application Serial No. 256,373, filed November 14, 1951, in the name of J. H. Haslam and assigned to the assignee of the present application), 20 parts of beta-diethylaminoethyl methacrylate and 0.5 part of alpha,alpha'-azodiisobutyronitrile were heated togetherfor 5 hours at 65 C. in the manner of Example III above. There was thus obtained an 80/ 20 sec.-capryl methacrylate copolymer as a fuel oil-soluble, soft, sticky, rubbery resin.

EXAMPLE VIII parts of tridecyl methacrylate from a commercially available, branched-chain primary tridecyl alcohol, 40 parts of beta-diethylaminoethyl methacrylate, 60 parts of styrene and 1 part of alpha,alpha-azodiisobutyronitrile were heated for 20 hours at 65 C. in the manner of Example III. There was thus obtained a 50/20/30 tridecyl methacrylate/beta-diethylaminoethyl methacrylate/ styrene copolymer as a fuel oil-soluble, rather stiff, rubbery resin.

EXAMPLE IX A mixture of 180 parts of lauryl methacrylate, 14.5

agie f; an

EXAMBEE I I-X-A To a solution. of 90 parts. of the, above lauryl'. metha acrylate/N-(beta-vinyloxyethyl)formamide copolymer in about 400 parts of benzene was. added" 1110 parts.of:1 8%.:' aqueousi hydrochloric acid. and the resulting. mixture heated at a gentl'et refiux for one hour with. stirring. The resulting: creamy emulsion wasxreatedwith anexcess. of 20% aqueous sodium hydroxidezsolutionand;the: organic layer thereby obtained removed, washed well with water and any retained benzene-water removed by evaporation at steam bath temperatures under atmospheric pressure and finally under reducedpressure. There was thus obtained a fuel oil-soluble, highly v-iscous, tacky copolymer which upon analysis was found to contain 0.25% primary amino nitrogen, indicating the presence of 1.4% combined beta-vinyloxyethyl'arnine' groups.

EXAMPLE X were heated for 5 hours -at'65" C. There Wasrobtained" a 90/10 ar-dodecylstyrene/beta diethylaminoethyl metha acrylate copolymer as; a fuel oil-soluble, high viscous. product, tack-yzat room temperature.

The polymer additives'used in preparing; the fuel oil". compositions of this invention can be incorporated in the fuel oils by simply blending with stirring at ordi nary temperature or, ifrdesired.a.mixtureiofftheafuelioil and the additive polymer or polymers can be heated to elevated temperatures, e. g., l00l30 C. with agitation.

In the tables given hereinafter showing the results of subjecting fuel oil compositions of the present invention to: various;- tests-;, all. proportions are byweight: unless otherwise stated;

An accelerated v storage. test" was v carried out on; samplesof catalytic crackeclfuel oil #2 distillatetinhibited by incorporating therein: small amounts of var-iousapolymerse In-this particular test, cc. portions. the treated fuel oil containedin-ZO cc.. clearglass vented vialsgwere exposed to indirect sunlight at room-.tempera-.- ture, Theisamplesiwere observed daily and the number of- .daysrequiredfor the. first appearance; of'haze; and cloudiness. in theoil represent the appearance of? oil insoluble products .which is the: first indication of sludge and-precipitateformationin the-oil. In some instances, the first appearanceof sedimentwas. also. noted,.this..usua ally occurring somewhat later. The. results. of: this; ac-. celeratedstorage testare given in' Tables: In to-VI- below withtrespect to,-var iouscopolymers. inivarious concentrate tionsiexcept for Table -II;I-'-A- where: a modified test as. 6X1 plained in connection with that table, was used.

h 6': male 1.-

MnzlHAQRY-mms; AND: martian-141s? on VARIOUS? ALCOHOLS Added' c'zi el'ymer 92 Octadeeem' l methacnylate/diethylaminoethyl methacrylate 88/17 0.005 s s" 23' 6" 10. Octylphenyl methacrylate/dlethylaminoethyl methacrylate 90/10 0.05 6 (4) 7 (0) 11-. nsButylmethacrylate/di g i ethy m'iiioeth'yl meme: p f

Copolymer #11, which does not fall within the scope of the invention, illustrates that copolymers without side chains containing at least eight carbon atoms, show no appreciable inhibiting action in this test.

VARIATION IN OOBOLYMER. CONCENTRATION.

v! v Concenappearance ot Added Copolymer tration, percent Haze '(controly aminoethyl methacrylate=/20 0.003

Table "III VARIATIONIN RATIO OF mmr-Mnmoomcmnmrs.mu: IN3COPOLYM1ER CONCENTRATION Days'tbfnrs t'f I a earance-o--- Ratio tL'auryl methacrylate/diethybp. aminoethyl methaerylate S d e i- Haze ment- 1. Control' 4% f i 3 fi i; 13 3. 915/25. ,,g';g 13 0. 00s; 5 17. 0.005" 7 17 0.00s, 8;; 17.v (X005 3* .2 0.005- 3' 5 0.00.5. 2 2

payment app'arancenf Y Concerts- Copolymers #8 and #9 do not embody the invention inasmuch as they contain in excess of 3.5%, by weight, of basic amino nitrogen due to the large proportion of diethylaminoethyl methacrylate, and actually give poorer results than the control.

Table III-A below supplements Table III. The test used here differed from that in Tables I to VI in that the samples were maintained at 110 F. in the dark, the weeks to the first appearance of sediment being observed. The fuel oil used was Sinclair 100% fluid catalytically cracked light cycle oil.

Polymer #2 is not an embodiment of the inventionsince it is a polymer of only a single polymerizable unsaturatedscompoundand contains no basic amino nitrogen at all.

Table IV VARIATION IN THE BASIC COMONOMER [First component is lauryl methacrylate (LM) throughout.]

Days to first C appearance of mean- Basic Comonomer Ratio nation 8 di 9 Haze ment 1. Control 4 7 2. LM/bota-aminoethyl vinylether 07 3 005 6 17 3. LM/beta-aminoethyl vinylether 95: 5 005 6 4. Control 4 5 5. LM'IN-tertiary-oetylaminoethyl methacrylate 80 :20 005 7 17 6. LM/alpha-mothyl-benzylaminoethyl methacryl ate. 85 15 005 5 9 7. LM/mothacrylanilide/vinyl beta-diethyl-aminoethyl etherx. 85:7. 5:7. 5 005 5 8 8. LM/dimethylarnino-methylstyrene 9.5: 5 005 7 23 9. LM/2, dime l 90: 10 005 5 20 aminopropyl methacrylate. s 10. LM/beta(N,N-di-2-ethylhexylamino ethyl methaerylate. 60 :40 005 7 7 11. LM/Bis(diethylaminoethyl) malinate 90:10 005 6 7 12. Control 5 l 13. LM/i-vinyl pyridine 9, 5

14. Control 4 15. LM/methacrylanihde/ glycidyl methacrylate +diamyl amine (See Example III) s 85/10/5 0.005 13 16. Control 1 17. LM/2-metl1yl-5-vinyl pyrid' ine 90/ 0. 003 6 18. -LM/diisopropy1aminoethyl methacrylate 80/20 0. 012 8 8 Table V VARIATION IN LONG-CHAIN COMPONENT Days to first ap- Concenpearance of Oopolymer Ratio tration, percent Haze Sediment 1. Control 4 6 2. Lauryl iumarate/DB 93/7 .005 7 17 3. Vinyl laurate/beta-(N,N-dimethylam ino) ethyl vinyl ether 90/10 005 5 13 4. Vinyl laurate/DB /20 .0025 5 5. Octylphenyl methacrylate/DB /10--- 005 6 7 6. Control 5 6 7. Vinyl lauryl ether/vinyl diethylamino ethyl ether 80/20 05 7 13 8. Control 4 6 9. Cyclohexyl styrenelN-tertiaryoctylaminoethyl methacrylate 67/33 05 6 6 10. Dodecyl styrene/DB 00/10 .005 7 13 .05 20 23 11. Octadecyl styreneM-vinyl pyridine 1 DB is diethylaminoethyl methacrylate.

Table VI COPOLYMERS WITH THREE COMPONENTS Days to Concen- Copolymer Ratio tration, 2 53 percent of haze 1. Control 4 2. LM lStyrene/DIB 50 1 3 005 8 3. LIM/N-ter 30'50120 005 7 4. LM/Butadienc/DB 17. 5:65:17.5 l 5. Control 6 6. LM/methacrylanilideI2-methyl--vinylpyridine 85/10/5 0. 012 27 7. Decyl acrylate/methacrylanilide/DB 85/ 7. 5/7. 5 p 0. 003 13 8. LM/methacrylanilide/p-dime t h y l a m i n omethylstyrene 85/10/5 0 012 20 9. Control 1 10. LM/methacrylanilide/DB 85/1515 0.006 18 1 LM is technical lauryl methacrylate. DB is diethylaminoethyl methacyrylate.

Samples of catalytic cracked fuel oil #2 distillate were inhibited by incorporating therein small amounts of technical lauryl methacrylate/diethylaminoethyl methacrylate 80/20 copolymer. The samples were subjected to an accelerated storage test in vented glass bottles at F. for 12 weeks in the dark. The samples were examined weekly for the first appearance of sediment and at the end of the 12 Weeks period the samples were compared in color using the ASTM NPA method and were analyzed for soluble and insoluble residue using the following method. The sample is filtered at room temperature by gravity through #5 filter paper. The container and filter paper are washed with naphtha. The filtrate is analyzed for soluble residue by steam jet evaporation. The insoluble residue formed during the aging test is dissolved from the container and filter paper with a 50-50 mixture of acetone and methanol and determined by air jet evapo ration according to ASTM Method D-525-46. Both sol of fuel. The results of the tests are as follows:

I Trib'le Vll' EEEEUT 0,11, TECHNICAL LAURYL METHACRYLATEL DIETHYL' MINOEI HYL METHAORY'LATE 80/20 OOPOLY- MER'. N": EUELaOILS STORED 12-.;WEEKS AT.-1l0- INT VEN'IED GLASS BOTTLES IN THE DARK Additive Soluble Insoluble Time to. Fuel Conc-q Residue ,-Residue,, F-irst'Ap- "NPA' W t. mg/100 Ina/100;: pearance of .Color Percent ml. ml. Sediment Low sulfur ther None 11 7 Gweeks... 4%

moiorrcatalytic': cracked.

Do 0.01" 4 4 Noneat12i 3 weeks".

High.rsulfun.therl-- None 10.. 7' loweeksn 4.

motor catalytic cracked i T Do 0. 01.. 5: 4 12 weeks.. 3%

Fluidzoatalytlc. None 13' 11 6-,weeks;.. 4

crackedi't i 2 Dn 0:01. 3;: 5.. .Noneat12 3% weeks;

These results show this copolymer is highly efiective in inhibitinggthe formationrofl-residue and is.also somewhat eifctiveinlstabilizingjhe color of, theoils;

' For purposes. of comparison with the above,. samples' ofjacata'lytic crackedNo. 2- fuel oil were; treatedlwith 0Z045wt. percent, off several differentv dispersing agents thatare, commonly employed as .lubricating oil"detergents., The sampleswere. subjected to'the. aging v test described. above, After twomonthsi storage in the dark at 110 inlventedfb'ottles all; samples contained as much or more precipitate than the untreated" control sample. The dis? persing agents tested are listedin Table VIII.

Table; Vllll Condition of Oil Sample Alter Dispersingykgent 2 Months Storage At 110 Efin-yented -Bottles None-(contmlsample).- .Ljghtpptn. Barium Petroleum .Sulionete More ppt. than control.

Much more ppt. than-control. More ppt. than control. Ppt. equal to control.

Octadeeyld'imethflamine-k phosphitez' Triethyl'ene tetramine+naphthenie Ethylene oxide condensation produot 'Pbt. edual to control. Alkylaten BenzeneiBariumg'Sultonates. QM'DEBLDDtl than :coutrole S1. more ppt than control. V

More ppti than control;

- S1. moreppt; than control:

T'he. -negativeresults ob'tair'ied with: theabove orthodox dispersing agents: commonly used 'im lubricating oils and whichi'might have b'een expected" to function eifectively: as stabilizers in fuel' oils'y are in 1 strikingcontrast to the rcsults'mbtainedmsinguhe instant copolymers asstabilizers forfuel 'oils:

Samples of badlyi-deteriorated catalytic cracked-*fueltoil No. 2' whichhad: been drum aged 'for four. years-in theab'sence of treating agents;- were evaluated in a pumping test aloneand 'together. with 0.0025 wt. percent oftech nioal lauryl metliacrylate/betardiethylaminoethyl methacrylate,- 80/ 20} copol'ymen In this-test one gall0n-portions of the oil under examination are charged 'intoasmall reservoir which is-' connected by a copper'piping-system' to a small Commerciahfiielbil-pump ancla'strainer assembly so arrange'd that'the sample-of'oil can tie-cycled indefinitely tlirough tliestrainer. At theend of-the cycling period? which is usually two' to' five days dependingmn thereto of-*p li.1gging of'the screen measured by means of a pressnrel gauge placed in the line; just ahead of the. screen; the screen is removed and the weight of solids collected on the screen is determined; a

One gallon samples of the aged No: 2 fuel -oil -were arouse 1 l0}. rival- 7, Inhotnrunslthe.screenlwas hadly, plugged bythe. insoluble. residuenpresent, in, the oil... When. another. one. gallonsampled ill 838M116 de terioratedoil that was ,treated. to: contain. O.0025.,.wt.1. percent: of. technical] laurylmetlfl acrylate/diethyl-aminoethyl methacrylate 80/20; cop oly:- mer; washcycled, theascreenirom the test assembly was, practically. free;o f;deposits.. The additive. had prevented, the insolublezresidue fromgadheringtothe.screen. The. quantities of,residue .adhering..to the screenare given-in Table IX..

Tables'IX' Wt.-oi 'De"-'- Hours Testxsampla posit on;

Oycled Sex-awning} ed uel. Ollalone- 4s 155 Aged'flFilel Oilfaldne... 90- 270* AgedaFuel; Ol1+0.002 7 wt pereen tech a1 laulyl methaclfyleteldiethylaminoethyl methacrylate 80/20 l. 120* 19:

The advantage obtained by the-use-of asm'all amount of a conventional metal' deactivator in combination Willione ofthe herein considered copolymers inthe-polymeri zation of -'fuel-' oil' 'is illustrated in the following test-z Samples of catalytic cracked No. 2" fuel oil distillate were inhibited by incorporatingthereim small amounts of technical lauryl methacrylate/diethylaminoethyl' meth'ac rylate;- 80/205 copolymer and di'-(2-hydroxybenzal)'-1 ,'2 propylenediamine; aconventional metal deactivator: The" samples were-subjectedto an accelerated" storage" test in -ventedgl'assbottles-"at l10-"'F5 for- 12" weeks in=tlie dark,- kt the end of the--12 weeksaging perio'dthe' samples-werean-alyzed for -solubl'eand insolubleresidue using It will be understood" that while: the foregoing i exam ples '-and tables-have= disclosed a; considerable=number of specific polymersaadapted-"for-use in the compositionsaof' the present invention, these 'aremerelyillustrative and' subjected to this pumping test for 45 and hours, respecthat the present invention broadly comprises a -fi1el oil containing" at= least -'0f001% by weight thereofof an oilsoluble, basie'" aminonitrogen-containing addition-type polymer 'offa pli-ira'lio," of "polymerizable ethylenically urrsaturated compounds at least one of'which is amine-freeand at leastone ofwhich contains atleast 8carbon' atoms; the polymer "containing-01%' to 3.5%, by weight thereof; of b asic amino'nitrogen.

The-polymers used in the present invention are actually copolymers-de'rived from at leasttwo different polymerizable compounds one '-'of-- which must be amine-free, at least-'one=--of-which-must contain from 8 to about 1'8 car-m atoms inan aliphatic hydrocarbon chain' which in the-"polymen is not: part of the main polymer chain, thereby *providing'an oleophilic'structure, and at leastone of which must contain a basic amino nitrogen structure, and the-*copolymersmust contain'at least 0.1% butnot more-than 325%; by weight thereof, of basic amino nitrogen, preferably-between 0.2% and 3;0%'. The-polymer can-be derived from-non only two diflerent polymerizable compounds as above but also fromoneor more additional polymerizable compounds that do not by themselves form oil-soluble polymers, providing the proportions are restricted to insure that the polymers have the requisite oil solubility and that no substantial change in the valuable properties of these polymers as sludge inhibitors and dispersants. A basic requirement is that the copolymer formed must have at least a limited solubility in the fuel oil, i. e., at least 0.001% by weight. The term oilsoluble is used herein to denote a solubility of at least 0.001%, by weight, of the polymer in the fuel oil.

As the oleophilic components of copolymers useful in the preparation of the improved fuel oil compositions of this invention there can be employed polymerizable esters, amides, ethers, and hydrocarbons characterized by the presence of at least 8 carbon atoms, preferably with 6 or more in a straight chain, and at least one carbon-carbon double bond capable of participation in free radical initiated addition copolymerization reactions. Examples of oleophilic components that come within the purview of this invention are: saturated and unsaturated long-chain esters of unsaturated carboxylic acids such as decyl acrylate, 3,5,5-trimethylhexy1 methacrylate, 9-octadecenyl methacrylate; unsaturated esters of long-chain carboxylic acids such as vinyl stearate; long-chain esters of vinylene dicarboxylic acids such as methyl lauryl fumarate; N- long-chain hydrocarbon substituted amides of unsaturated acids such as N-octadecyl acrylamide; long-chain monoolefins such as the alkyl or acyl substituted styrenes, e. g., dodecylstyrene, and the like. Obviously, these components can be employed alone or in various combinations and, in general, make up the majority of the polymeric additive in order to insure proper oleophilic character. The technical lauryl methacrylate obtained from the commercial mixture of long-chain alcohols in the C10 to Cm range derived from coconut oil is an especially useful oleophilic component of the copolymer but the group of acrylic and alkacrylic esters of aliphatic alcohols of at least 8 carbons are, in general, well suited as the oleophilic component of the copolymer.

The basic amino nitrogen-containing component that imparts sludge inhibiting and dispersant properties to the polymers useful in this invention, can be introduced through the use of appropriate copolymerizable monomers containing primary, secondary or tertiary amino nitrogenthat is attached ultimately to the chain of the polymer as part of an extralinear substituent group in which the nitrogen is joined extranuclearly only to nonbenzenoid carbon atoms. There can be employed in the copolymerization monomers such as glycidyl acrylate or vinyl chloroacetate which introduce groups reactive toward ammonia or amines and thus provide a means of attaching the necessary basic amino groups to the polymer chain. Attachment of the amino groups to the main copolymer carbon chain can be through strictly hydrocarbon structures or through ether, ester, or amide linkages.

Particular examples of the basic amino-containing monomers include the basic amino substituted olefins such as p-(beta-diethylaminoethyl)styrene; basic nitrogencontaining heterocycles carrying a polymerizable ethylenically unsaturated substituent, e. g., the vinyl pyridines and the vinyl alkyl pyridines such as 2-vinyl-5-ethyl pyridine; esters of basic amino alcohols with unsaturated carboxylic acids such as the alkyl and cycloalkyl substituted aminoalkyl and cycloalkyl esters of the acrylic and alkacrylic acids, e. g., beta-Inethylaminoethyl acrylate, 4-diethylaminocyclohexyl methacrylate, beta-beta-didodecylaminoethyl acrylate, and the like, unsaturated ethers of basic amino alcohols such as the vinyl ethers of such alcohols, e. g., beta-amlnocthyl vinyl ether, beta-diethylaminoethyl vinyl ether, and the like; amides of unsaturated carboxylic acids wherein a basic amino substituent is carried on the amide nitrogen such as N-(beta-dimethylaminoethyl)- acrylamide; polymerizable unsaturated basic amines, e. g., diallylamine, and the like. In this specification and claims the term-basic amino nitrogen is used in the generic 12 sense to cover the primary, secondary and tertiary amine including, as stated above, the basic nitrogen-containing heterocycles.

Because of their relatively greater basicity and more elfective sludge suspending and inhibiting properties, the polymerizable ethylenically unsaturated compounds containing a basic tertiary amino group are preferred and those having only primary basic amino groups are least desirable. Particularly outstanding and readily available basic amino nitrogen-containing components are the alkyl and cycloalkyl substituted tertiary aminoalkyl and cycloalkyl esters of acrylic and alkacrylic acids.

The basic amino nitrogen-containing component of the copolymer must be present in a minor proportion by weight corresponding to no more than 3.5% and no less than 0.1% of basic amino nitrogen by weight of the polymer. Above the higher level, which, for example, corresponds to about 50% by Weight of amino monomer in a lauryl methacrylate/beta-diethylaminoethyl methacrylate copolymer, and at less than the lower level, the performance of the polymer as a sludge inhibitor falls off rapidly. It is preferred that the basic amino nitrogen content be within the range of 0.2% to 3.0% by weight of the polymer.

While the polymers as herein defined are highly effective as fuel oil stabilizers, homopolymers of aminoethyl methacrylates, preferred components of the copolymers used in this invention, are without effect on the formation of sediment in fuel oils. Even when they contain long hydrocarbon chains they are ineffective and actually accelerate formation of sediment in some instances.

Table XI shows the effect of various aminoethyl methacrylate homopolymers in the test used with respect to Table I.

The sludge-inhibiting and dispersing polymers used in this invention can contain limited amounts of copolymerizable components that do not necessarily contribute either to improve solubility or inhibiting and dispersing action but merely serve as fillers or extenders for the active components. Typical examples of these filler com ponents include the well-known shorter chain ethylenically unsaturated addition polymerizable monomers such as the vinyl and allyl formates, acetates, propionates, butyrates, and the like; polymerizable unsaturated short-chain hydrocarbons, e. g., the monoolefins such as ethylene, propylene, isobutylene, styrene, vinyltoluene, and the like, and the short-chain dienes such as 1,3-butadiene, isoprene, and the like; unsaturated short-chain carboxylic acids and their derivatives such as the alpha-methylene carboxylic acids and their derivatives, e. g., acrylic acid, methyl methacrylate, acrylonitrile, methacrylamide, and thelike; the short-chain unsaturated ethers, particularly the vinyl and allyl ethers, e. g., ethyl vinyl ether, butyl vinyl ether, allyl glycidyl ether, and the like. These and other familiar monomers that are available at moderate cost, can be employed for this purpose in proportions ranging up to as much as 79%, by weight, in representative polymers although it is preferred they should not exceed by weight of the polymer.

In addition; inclusion of minorproportions 'oftzNshydroacarbon-substituted; amides of unsaturatedicarboxylicsacidsz wilHie-found-beneficial; Especially suitablesasspolymerize able "components of the polymer are the -N-hydrocarbonasubstituted acrylamides including N-tert-iary butylaoryl amide; N-tertiary-octylacrylamide, and} particularly, the

Naryl'a'crylamides such as methacrylanilidea andz acryl'a anilid e:

The polymers employed 'in the-improved'fuel .oihcompo.-

sitionsof 'thisinvention can be represented by thecfollowe ing schematic formula:

.CY' Q (|1 C" G (M) n: (MM.

WhereifM' is'the' structural unit joining ,tli'e various subfstituentgroups to the main chain of thepplymer;'R6 is-'- the. required oleophilic. structure, Rb; isi'the "basici amino contaiilingiistructure that imparts sludge" dispersant); and Ri'istheoptional extender structure; and' x; y and z-repre sent the proportions of these various structures ina" the in which the nitrogen is bonded extra nuclearly only to hydrogen or aliphatic carbon and in which A is a hydrocarbon radical of 1-18, preferably 2 to 6 carbon atoms, B and D are hydrogen or hydrocarbon radicals of no more than about 18 and, preferably, no more than 6, carbon atoms, and B or D can be joined with A to form heterocycle. The proportions of the various structures in the polymer, as represented by x, y and z in the schematic formula, normally will be in the range; x from 20% to 99%; y from 0.5% but, preferably from 1% to 50%; and z from up to 79% but, preferably, only up to 65%, all percentages being by total Weight of the polymer. Within these ranges, optimum proportions will be determined both by the properties contributed to the polymer by the individual polymerizable components going into its composition and the particular properties of the polymer which it is desired to emphasize.

The concentration of the copolymer in the fuel oil will vary to some extent depending on the effectiveness of the particular copolymer, the particular fuel oil, and the degree of stability required. Generally, a concentration of at least 0.001%, by weight of the fuel oil, will be used and a concentration of 0.1% will not be normally exceeded except where master batches containing 50% or more of the copolymer, by weight of the oil, are made up for convenience in processing and shipping prior to dilution of the oil. Concentrations of between 0.002% and 0.01%, by weight of the fuel oil, are usually adequate.

The copolymers may be incorporated and used in the fuel oil together with conventional antioxidants and metal deactivators as illustrated in Table X, such additives sometimes being employed to impart other desirable characteristics to the oil.

The present invention is applicable in the stabilization of any fuel oil which upon storage normally tends to undergo deterioration. It is particularly useful in the stabilization of fuel oils entirely composed of catalytic cracked oil or containing a substantial proportion of catalytic cracked oil, e. g., at least 20%, by weight thereof, inasmuch as the catalytic cracked fuel oils are notoriously subject to deterioration on storage.

An advantage of this invention is that it provides an economicala' ands practical;- meanss of; eifectit' el-y. stabilize ingsfuelaioilsi- An outstanding advantagesiszthat:itzproa vides a... meanssforr-ther productions: of.:-- catalyticza cracked fuelioilsl withx greatlyrirnproved resistance to: sludge! and. gum formation on storage and, to some .extennofitimr-m proved-,Ecolonstability:

Ar.stillfifurther advantage:ofs-this';invention isrthatcthe; polymersmsedaalso:have rustrtinhibiting:properties. To; illustrate; a v 8.0/20. :copolymerr of technical; lauryl met-ha acrylate" and diethyl'aminoethyl methacrylate was disesolved in :aucrackeclzfuel:oilrdistillateesto.'mconcentratiorr. ofi '0.002-51% .by.weight=:. Thessolutiomiwasathen stored in; a vented iclean glfiSSiJlJOItlCf: exposed to indirect:sunligl 1't=' at-rroom temperature; the:. bottleacontainings water:- in its lowerthirdi- A5: strip offmildisteel-iwasiainsertedt sot ass to: extends. through thei water; oil; andrairr'phaseswinz thee bottle. This zis an accelerated Ttestlforzth sting .which. occursuwhen a fuelioil containing:watenris-=storedr in; as, steelcontainen Eon comparisoman untreatedaoiltandz. an oilcontaining-var commercial: rnstrinhibitor; wercesimilarlystored'i After two .=days; thee steel. strip" in: the latter two 1 cases showed P-rusting: n thewwaterzphase: blutztintz th'ez case of' 'the -oil :containing.,.the dis'solvedpolymer; no rusting took place atx any point on steel? strip during; storage for seven daysr As 1 many apparently; widely difirent embodiments of: this invention may be made without departing: from zthe: spiritiand scoperthereof, itiisZ- to: berunderstoodl that the invention? is not-'- limited to thea: specific: embodiments" thereof except as defined in -the appended claims:

The invention claimediii .1

1i". A petroleum base fuel oil containing as 'a; sludge; inhibiting and dispersingragenti'atileasti030011%i-bwweiglita of -am oil solublepl basictamino' nitrogemcontainingzaddi l tion type copolymer containing in combined form as its essential monomeric components copolymerizable ethylenically unsaturated compounds each containing only one polymerizable ethylenic linkage, at least one of which component is amine-free and contains from 8 to about 18 carbon atoms in an aliphatic hydrocarbon chain which in the polymer is not part of the main chain, and one of the components as it exists in the polymer containing a basic amino nitrogen in the side chain, said copolymer containing 0.1% to 3.5% by weight of basic amino nitrogen and said copolymer having an inherent viscosity of 0.1 to 3.0 as determined at 0.1% weight-volume concentration in benzene at 25 C.

2. A fuel oil composition as set forth in claim 1 wherein said fuel oil comprises at least about 20%, by weight thereof, of catalytic cracked oil.

3. A fuel oil composition as set forth in claim 2 wherein said oil-soluble polymer is present in a proportion of 0.002% to 0.01% by weight of said fuel oil.

4. A fuel oil composition as set forth in claim 1 wherein said oil-soluble polymer is present in a proportion of 0.002% to 0.01% by weight of said fuel oil, has an inherent viscosity of 0.2 to 1.0 as determined at 0.1% weight/volume concentration in benzene at 25 C., and contains 0.2% to 3.0%, by weight thereof, of basic amino nitrogen.

5. A petroleum base fuel oil containing as a sludge inhibiting and dispersing agent at least 0.001% by weight of an oil soluble, basic amino nitrogen-containing addition type copolymer containing in combined form as its essential monomeric components copolymerizable ethylenically unsatuated compounds, one of which is from the group consisting of acrylic and alkacrylic esters of aliphatic alcohols of from 8 to about 18 carbon atoms and one of the components containing a basic tertiary amino group in the side chain, said copolymer containing 0.1% to 3.5% by Weight of basic amino nitrogen and said copolymer having an inherent viscosity of 0.1 to 3.0 as determined at 0.1% weight/volume concentration in benzene at 25 C.

6. A fuel oil composition as set forth in claim 5 15 wherein said oil-soluble polymer is present in a proportion of 0.002% to 0.01% by Weight of said fuel oil, has an inherent viscosity of 0.2 to 1.0 as determined at 0.1% weight/volume concentration in benzene at 25 C., and contains 0.2% to 3.0%, by weight thereof, of basic amino nitrogen.

7. A petroleum base fuel oil containing as a sludge inhibiting and dispersing agent at least 0.001% by weight of an oil soluble, basic amino nitrogen-containing addition type copolymer containing in combined form as its essential monomeric components copolymerizablc ethylenically unsaturated compounds, one of which is from the group consisting of acrylic and alkacrylic esters of aliphatic alcohols of from 8 to about 18 carbon atoms and one of the components is from the group consisting of alkyl and cycloalkyl substituted tertiary aminoalkyl and amino cycloalkyl esters of acrylic and alkacrylic acids, said copolymer containing 0.1% to 3.5% by weight of basic amino nitrogen and said polymer having an inherent viscosity of 0.1 to 3.0 as determined at 0.1% weight/volume concentration in benzene at 25 C.

8. A fuel oil composition as set forth in claim 7 wherein said oil-soluble polymer is present in a proportion of 0.002% to 0.01% by weight of said fuel oil, has an inherent viscosity of 0.2 to 1.0 as determined at 0.1% weight/volume concentration in benzene at 25 C., and contains 0.2% to 3.0%, by weight thereof, of basic amino nitrogen.

9. A petroleum base fuel oil containing as a sludge inhibiting and dispersing agent at least 0.001% by weight of an oil soluble, basic amino nitrogen-containing addition type copolymer containing in combined form as its essential monomeric components copolymerizable ethylenically unsaturated compounds, one of which is from the group consisting of acrylic and alkacrylic esters 16 of aliphatic alcohols of from 8 to about 18 carbon atoms and one of the components is beta-diethylaminoethyl methacrylate, said copolymer containing 0.1% to 3.5% by weight of basic amino nitrogen and said polymer having an inherent viscosity of 0.1 to 3.0 as determined at 0.1% weight/volume concentration in benzene at 25 C. 10. A petroleum base fuel oil containing as a sludge inhibiting and dispersing agent from 0.002% to 0.01% by weight of an oil soluble, basic amino nitrogen-containing addition type copolymer containing in combined form as its essential monomeric components copolymerizable ethylenically unsaturated compounds, one of which is lauryl methacrylate and one of which is beta-diethylaminoethyl methacrylate, said copolymer containing 0.1% to 3.5% by weight of basic amino nitrogen and said copolymer having an inherent viscosity of 0.1 to 3.0

as determined at 0.1% weight/volume concentration inv benzene at 25 C.

11. A petroleum base fuel oil as set forth in claim 1, containing from 0.1% to about by weight of the oil soluble, basic amino nitrogen-containing addition type copolymer.

References Cited in the file of this patent UNITED STATES PATENTS 2,138,763 Graves Nov. 29, 1938 2,311,548 Jacobson et a1. Feb. 16, 1943 2,448,542 McQueen et a1. Sept. 7, 1948 2,666,044 Catlin Jan. 12, 1954 OTHER REFERENCES Petroleum Engineer, November 1950, pages C-31 and C-32. 

1. A PETROLEUM BASE FUEL OIL CONTAINING AS A SLUDGE INHIBITING AND DISPERSING AGENT AT LEAST 0.001% BY WEIGHT OF AN OIL SOLUBLE, BASIC AMINO NITROGEN-CONTAINING ADDITION TYPE COPOLYMER CONTAINING IN COMBINED FORM AS ITS ESSENTIAL MONOMERIC COMPONENTS COPOLYMERIZABLE ETHYLENICALLY UNSATURATED COMPOUNDS EACH CONTAINING ONLY ONE POLYMERIZABLE ETHYLENIC LINKAGE, AT LEAST ONE OF WHICH COMPONENT IS AMINE-FREE AND CONTAINS FROM 8 TO ABOUT 18 CARBON ATOMS IN AN ALIPHATIC HYDROCARBON CHAIN WHICH IN THE POLYMER IS NOT PART OF THE MAIN CHAIN, AND ONE OF THE COMPONENTS AS IT EXISTS IN THE POLYMER CONTAINING A BASIC AMINO NITROGEN IN THE SIDE CHAIN, SAID COPOLYMER CONTAINING 0.1% TO 3.5% BY WEIGHT OF BASIC AMINO NITROGEN AND SAID COPOLYMER HAVING AN INHERENT VIXCOSITY OF 0.1 TO 3.0 AS DETERMINED AT 0.1% WEIGHT-VOLUME CONCENTRATION IN BENZENE AT 25* C. 